Electrical loads, such as lamps, ceiling lighting fixtures, thermostats, shades, etc., may be controlled using load control devices. Such load control devices may be configured for wireless communication. For example, a lamp may be electrically connected, for example plugged in, to such a load control device. The load control device may be, for example, a dimmer switch configured for radio-frequency wireless communication (e.g., an RF dimmer switch).
FIG. 1 depicts an example prior art lighting control system 10 that includes a table top RF dimmer switch 20 and a lamp 30 plugged into the dimmer switch 20, such that the dimmer switch 20 controls the amount of power delivered to the lamp 30. The dimmer switch 20 is electrically connected to an electrical circuit 40 that includes an alternating current (AC) power source 41 and an AC outlet 42 electrically connected to the source 41. The outlet 42 includes a switched receptacle 43 and an unswitched receptacle 44. The electrical circuit 40 also includes a wall-mounted switch 46 that is coupled in series electrical connection between the source 41 and the switched receptacle 43.
The lamp 30 is also controlled by the wall-mounted switch 46. The dimmer switch 20 includes a plug 22 that is plugged into the switched receptacle 43 and the lamp 30 includes a plug 32 that is plugged into the plug 22 of the dimmer switch 20, such that the delivery of power to the lamp 30 may be controlled via the wall-mounted switch 46.
The lighting control system 10 also includes a plurality of devices configured to wirelessly communicate with the dimmer switch 20. As shown, the lighting control system 10 includes an occupancy and/or vacancy sensor 50, a daylight sensor 60, and a remote control 70, such as a remote keypad. The occupancy and/or vacancy sensor 50, daylight sensor 60, and/or remote control 70 may wirelessly communicate with the dimmer switch 20, for example to command the dimmer switch 20, using RF signals 90.
Though a user could plug the dimmer switch 20 into the unswitched receptacle 44, many users may prefer to combine the functionality of the dimmer switch 20 with the ability to switch power to the lamp 30 using the wall-mounted switch 46.
However, control of the illustrated lighting control system 10 may be compromised when power is removed from the switched receptacle 43. For example, when the wall-mounted switch 46 is flipped to the off position, the dimmer switch 20 may become unresponsive to wirelessly communicated commands, for example commands to turn on, turn off, or dim the lamp 30, from the occupancy and/or vacancy sensor 50, the daylight sensor 60, and the remote control 70. When the wall switch 46 is turned off, a wireless communication component of the dimmer switch 20, such as a receiver, may be unpowered and thus unable to receive the wirelessly communicated commands.